February 21, 2022

Advisors are now able to indicate that a student should not appear in the public Leaderboard. We added this feature because a number of advisor felt that younger and inexperienced students were embarrassed by seeing their names with a low score, and losing motivation to participate.


Jamuary 20, 2022

Congratulations to the 5,373 who competed in Contest #1. The scores were outstanding! Contest #2 is underway. Students who did not compete in the first contest are welcome to compete in Contest #2. There deadline to start the contest is Sunday, March 6th, at 11:59pm EST. Please don't let your students wait until the last day - why risk technical glitches or other events that are not in the student's control to miss the deadline? Good luck in the contest!


December 1, 2021

Students should first look in their spam folder; if the email is not there, and if the email address is a school email, the chances are that the email is being block by your school. Please reach out to your school's IT folks and have them whitelist email from


November 18, 2021

We have partnered with RaiseExamScores to provide online courses containing previous years' ACSL problems. There are currently 5 courses available: the Senior, Intermediate, Junior, Elementary, and Classroom divisions from the 2020-21 season. Students register for a course directly on their site, A subscription to each course is valid for 9 months. Please direct all questions and issues to the folks at RaiseExamScores, at

We hope that your students enjoy this opportunity.

2022 Registration

The 2021-22 registration form is now active!

There is one change we are making this year in the format of teams: A school may register multiple teams in each division! Thus, a school with, say, 13 active students in the Intermediate Division could be a single team (as in past years), two 5-score teams (one with 6 students and on with 7 students), one 5-score team and two 3-score teams, and so on. Conversely, there is a limit to the number of student that can be on a single team (20 students on a 5-score team; 12 students on a 3-score team).

We are allowing multiple teams so that more students in the larger schools will have their score counted as part of a team score. We are limiting the size so that there is some balance of competition between small schools and organizations and large ones.

2021 WRAP-UP

Congratulations to all participants in the 2020-21 season. By and large, the online format worked out well, and students, as usual, impressed us with their creative solutions to the problems!

Check back here in mid-July to learn about changes planned for the 2021-22 year, and to register your school or organization.


29 April 2021

When teams registered, ACSL sent a certificate to the team advisor. That certificate is given to the most deserving team member as determined by the team advisor.

Based upon cumulative scores after Contest #4, ACSL will send a certificate to the top scoring student(s) in each division in each state. The top scoring team(s) in each division in each state will also get a certificate.

For the ACSL Finals, the top scoring students in each division will get a prize and a certificate.

All the certificates will be mailed to the team advisor for distribution to students. The prize will be sent directly to the student.


23 March 2021

The information here has been superseded by the Finals 2021 webpage.


2 December 2020

The ACSL tests must be completed individually. After students have completed the test, it's a great idea to work together to go over the tests, to learn from each other's mistakes, compare programming solutions, and to collaborate on the "most perfect" programming solution.

HackerRank requires that students are required to sign the following statement of honesty before starting:

I will not consult/copy code from any source including a website, book, or friend/colleague to complete these tests, though I may reference language documentation or use an IDE that has code completion features.

HackerRank has developed sophisticated algorithms for detecting plagiarism in programming solutions. Students found to be collaborating will score 0 points for that test.


27 November 2020

Contest #1 is underway and scores are trickling in! Congrats to advisors and students who have successfully navigated the new online platform.

Student results are updated on the ACSL Leaderboard every hour; if you don't see your results within an hour (okay, give it a couple of hours just in case everybody doing distance-learning on Zoom is slowing down the Internet pathways!)

Registrations will be accepted until January 1, 2021.

Results from Contest #1 will be accepted until January 18th at midnight (11:59pm), New York time.

What's new in ACSL 2.0?

13 September 2020

We hope that you are well, back at school in some form and thinking about ACSL. With many schools in remote-learning mode, ACSL has embraced a number of changes to support schools that are not physically meeting.

What's the same?

  1. The format of the contests in each division - short problems and a programming problem

  2. The ability to fit the contests into your school schedule and model

  3. The quality content and questions matched to student experience

What has changed?

  1. Registration is now online

  2. All divisions support 3-person teams

  3. The short answer test and programming problem will be administered online with automatic scoring and reporting. There is no need for an advisor to score the shorts, run the programs on the test data, upload scores and files, and so on.

  4. Students can take both tests from home.

  5. The All-Star Contest will be the online ACSL Invitational Finals.

  6. Last year's question set (2019-20 Vol. 42) is available in hardcopy format only, and sent by US mail. All other contest volumes are still available as files delivered by Dropbox.


Registration for 2020-2021 season is now open. Advisors may register their teams using this online form.


15 August 2020

The June 2020 newsletter of the Computer Science Teachers Association (CSTA) featured a "member spotlight" on ACSL's very own, Carlen Blackstone. In the article, she talks about her experience teaching over the past 40 years, some insight she’s gained, and how she’s still involved in computer science. Read all about it.

2019-2020 season review

1 July 2020

ACSL has been challenging students in computer science since 1978 and has evolved a great deal over those years especially in the expansion of the League to international venues, most recently in Korea and China, but the school year 2019-20 was like none other.

Until March, 2020, most schools operated as usual, but the COVID-19 pandemic changed everything as schools immediately converted to on-line learning. We realized that the only way for us to complete the year was to host a completely on-line individual Finals competition. That made it possible to invite students to participate from all 5 Divisions, including both Elementary and Classroom Division participants for the first time.

Students were invited to participate if they had high individual scores on the 4 regular season contests. On Saturday, May 23 we hosted the Finals via YouTube for over 1,000 students in grades 3-12 using the HackerRank platform for the programming problems and Google Forms for the Short Problems part.

Prizes were awarded to nearly 250 students complements of Google. One of our Executive Team members, Carlen Blackstone, who taught computer science at Emmaus HS in Emmaus, PA, invited 29 of her former students to host breakout Zoom meetings about how ACSL has helped them in college and beyond. She was also featured in the July CSTA+ Newsletter.

This endeavor has propelled us into making many new changes for the 2020-21 school year. Please join us in this adventure!